This is a continuation and extension of our longitudinal prospective investigation of childhood depression (diagnosed according to the DSM-III) with youngsters 8-13 years of age. The objectives include: a) the nosological study of the depressive disorders in juveniles with respect to clinical presentation, course (including recovery rates and later affective and nonaffective disorder sequelae), and anamnestic, demographic, parental, and familial psychiatric history variables, (b) preliminary study of the prognostic value of the childhoood depressive disorders for late adolescent and early adulthood adjustment, and (c) testing of the explanatory power and pragmatic value of cognitive-development and pubertal stage vis-a-vis depressive symptom expression and depressive-disorder parameters. The study entails sequential S recruitment and a repeated measures design in the context of a naturalistic follow-up. The target cohort of 120 depressed Ss will be youngsters referred to child psychiatric- and medical-outpatient clinics who meet the study's inclusionary criteria. They will be followed for a minimum of four and a maximum of ten years. The target Ss' characteristics, and their clinical course for the first five years will be compared with data from an age-matched psychiatric comparison group of 49 Ss. The comparison Ss represent a consecutive series of child psychiatric outpatient referrals with various nondepressive conditions who will be followed for five years. Both cohorts will be assessed repeatedly via a comprehensive battery that includes a semi-structured psychiatric interview, standardized parent- and child-rated scales, pediatric examination, cognitive-stage determination, and evaluation of familial psychiatric history. Pertinent variables (e.g. clinical psychometric, and medical data) will be assessed independent of each other. This study will contribute to a more valid nosology of the childhood depressions; to the field of developmental psychopathology; and to the integration of the areas of "child" and "adult" affective disorders. By documenting the existence and course of the depressions in juveniles, the findings will stimulate the development and testing of efficacious treatment and intervention methods for depressed youth. The longitudinal study of cases may also provide a further perspective on the affective disorders of adulthood which constitute a "number one" mental health problem.